Autor:innen:
I. Wagenhäuser (Würzburg, DE)
K. Knies (Würzburg, DE)
V. Rauschenberger (Würzburg, DE)
M. Eisenmann (Würzburg, DE)
M. McDonogh (Würzburg, DE)
N. Petri (Würzburg, DE)
O. Andres (Würzburg, DE)
S. Flemming (Würzburg, DE)
M. Gawlik (Würzburg, DE)
M. Papsdorf (Würzburg, DE)
R. Taurines (Würzburg, DE)
H. Böhm (Würzburg, DE)
J. Forster (Würzburg, DE)
D. Weismann (Würzburg, DE)
B. Weißbrich (Würzburg, DE)
L. Dölken (Würzburg, DE)
J. Liese (Würzburg, DE)
O. Kurzai (Würzburg, DE)
U. Vogel (Würzburg, DE)
M. Krone (Würzburg, DE)
Introduction
Rapid antigen tests for SARS-CoV-2 are fast, broadly available and inexpensive. However, previous studies have shown substantial differences in sensitivity and specificity. Published data from a first analysis including 5,171 parallel samples showed a large difference in sensitivity between manufacturers’ data and clinical use (EBioMedicine 2021,69:103455), but virus variant dependency of antigen rapid detection tests (RDT) is a broadly discussed topic.
Methods
In this prospective follow-up study, three RDT from three manufacturers (nal von minden NADAL®, Abbott Panbio™, MEDsan®) were compared to quantitative reverse transcription polymerase chain reaction (RT-qPCR). In total, 21,157 oropharyngeal swabs were analyzed. Cycle threshold (Ct) values of all RT-qPCR positive samples were determined.
Results
Overall, the sensitivity of RDTs was 42.86% (95%CI: 35.89%-50.12%) and the specificity 99.69% (95%CI: 99.61%-99.76%). Sensitivity negatively correlated with RT-qPCR derived Ct values. With considerable viral load (Ct ≤ 15), sensitivity was 100.00% and decreased to 75.00% (15 < Ct ≤ 20), 54.55% (20 < Ct ≤ 25), 24.00% (25 < Ct ≤ 30) to 5.00% in samples with a Ct>30. The negative predictive value in the study cohort was 99.51% (95%CI: 99.40%-99.59%), the positive predictive value 54.55% (95%CI: 46.37%-62.48%). No significant differences in sensitivity or specificity could be observed between the three manufacturers and between samples with wild type, alpha, and delta variant.
Conclusion
RDTs are a reliable method to diagnose SARS-CoV-2 infection in patients with a presumable higher viral load independently from spike protein mutations. RDTs may be a valuable addition to RT-qPCR testing as they may detect infectious patients before RT-qPCR results are available and offer the opportunity of broad repeated population testing. Data on antigen rapid test performance regarding the Omicron variant will be presented at the conference.